<?php
/**
 * Zend Framework
 * LICENSE
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 * @category Zend
 * @package Zend_Paginator
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 * @version $Id: Sliding.php 24593 2012-01-05 20:35:02Z matthew $
 */
/**
 *
 * @see Zend_Paginator_ScrollingStyle_Interface
 */
require_once 'Zend/Paginator/ScrollingStyle/Interface.php';

/**
 * A Yahoo! Search-like scrolling style.
 * The cursor will advance to
 * the middle of the range, then remain there until the user reaches
 * the end of the page set, at which point it will continue on to
 * the end of the range and the last page in the set.
 * @link http://search.yahoo.com/search?p=Zend+Framework
 * @category Zend
 * @package Zend_Paginator
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 */
class Zend_Paginator_ScrollingStyle_Sliding implements Zend_Paginator_ScrollingStyle_Interface {

    /**
     * Returns an array of "local" pages given a page number and range.
     * @param Zend_Paginator $paginator
     * @param integer $pageRange (Optional) Page range
     * @return array
     */
    public function getPages (Zend_Paginator $paginator, $pageRange = null) {
        if ($pageRange === null) {
            $pageRange = $paginator -> getPageRange ();
        }
        $pageNumber = $paginator -> getCurrentPageNumber ();
        $pageCount = count ($paginator);
        if ($pageRange > $pageCount) {
            $pageRange = $pageCount;
        }
        $delta = ceil ($pageRange / 2);
        if ($pageNumber - $delta > $pageCount - $pageRange) {
            $lowerBound = $pageCount - $pageRange + 1;
            $upperBound = $pageCount;
        } else {
            if ($pageNumber - $delta < 0) {
                $delta = $pageNumber;
            }
            $offset = $pageNumber - $delta;
            $lowerBound = $offset + 1;
            $upperBound = $offset + $pageRange;
        }
        return $paginator -> getPagesInRange ($lowerBound, $upperBound);
    }

}